When a structural member is excited by a horizontal external force, torsion or similar horizontal movement may occur. Torsion, especially in high building structures or towers may have serious impact on the conditions of the structure or even result in a collapse.
Dampers play an important role in the protection of structures, e.g. houses or similar building structures, and they exist in numerous variants. Dampers are typically dampening the motion by means of a frictional force between two moving parts attached between structural members of the building or by means of a fluid being pressed to flow between two chambers through a restricted tube. Some dampers are actively changing the dampening effect corresponding to external conditions, and other dampers are passive produce and even more costly to assemble into a structural member of a building. Typically a building have to be designed for a specific damper, either due to the bulky design of the existing dampers or due to correlation between the structural characteristics of the damper versus the characteristics of the building.
Typically the existing dampers are adapted to individually dampen movement of the vertically mounted structural members of building structures. This result in the dampening of the movement of individual parts of the building in relation to other parts of the same building, which dampening may protect e.g. a building from collapsing. However, if the entire building is moved horizontally, e.g. rotationally, the building may be damaged severely, even though the individual structural members of the building is being dampened individually. Horizontal movement may occur e.g. if the foundation of a building is displaced by an earthquake or by similar vibrations transmitted through the ground.